With continuous development in the flat panel display technology, more and more display devices are provided with touch screens. At present, in accordance with working principles and media for transmitting information of the touch screens, the touch screens can be divided into four categories, i.e., resistive touch screens, capacitive sensing touch screens, infrared touch screens and surface acoustic wave touch screens, respectively. For the capacitive sensing touch screens, the In-Cell touch technology has become mainstream in the touch technical field and the new development direction in the future due to advantages such as low cost, low power consumption and capability of realizing multi-touch and so on.
At present, some of the In-Cell touch designs use a time-division scanning method, in which each scanning cycle is divided into a time period for a display operation and a time period for a touch operation, which affects the detecting frequency of the touch screen. Therefore, how to realize a touch function, improve the detecting frequency of the touch screen and reduce influence on display while displaying, has become a research hotspot nowadays.